The present invention relates to a combination implement for agricultural cultivation.
Combination implements of the above mentioned general type are known in the art. A known combination implement has a main frame which is liftably connected (for example with the aid of a three-point linkage) with a pulling or dragging vehicle and carries advantageously exchangeable cultivating device, for example a cultivating or cutting tool and/or power take-off shaft-driven device such as a time rotor or a circular harrow. It also has an auxiliary frame which carries a crumbler roller supporting the combination implement during cultivation and formed as an extension of the main frame, and also supported on the main frame, adjustable for height adjustment, about a transverse axis. Because of the arrangement of tools of different type, a single travel for cultivating the respective ground surface is sufficient. During cultivation the combination implement remains vertically movable relative to the pulling or dragging vehicle and is exclusively or mainly supported by the crumbler roller. Such an arrangement is advantageous since the crumbler roller rolls on the ground to be cultivated, which has only a small waviness. Thereby the entire combination implement performs relative to the ground only relatively small vertical movements, so that the working output is considerably improved. Moreover, the crumbler roller is axially loaded, so that the soil to be cultivated can be compacted by the crumbling roller in desirable manner. This is true also when the crumbler roller is of a type having a relatively small weight and correspondingly low manufacturing costs.
The height-adjustability of the auxiliary frame relative to the main frame makes possible the height adjustment of the tool arranged on the main frame in a simple manner relative to the crumbler roller. Moreover, the auxiliary frame can be formed as a conventional frame which is provided in general for cultivating implements and has a crumbler roller. The cultivating tools arranged on the main frame penetrate as a rule relatively deep into the soil, and therefore can in certain conditions strike against stones or similar compact formations under the ground surface. In this case the tool tends to deflect upwardly, whereas the rigid arrangement of the entire combination implement is lifted. This is connected, however, with an extraordinarily high loading of the respective tool, which in this condition can be broken.
It is basically known to arrange cultivating tools individually or as a whole in a springy manner. However, the respective construction is complicated and accordingly expensive. Moreover, the elastically springy arrangement of the cultivating tools undesirably affects its working output.